When Machine-to-Machine (M2M) devices are using Wireless Personal Area Network (WPAN) technology like IEEE 802.15.4 e.g. ZigBee, a device needs to be attached to the Internet through a M2M Gateway (GW). The M2M GW acts as the WPAN coordinator in this case. The attachment and configuration between the M2M GW and the device is one of the hardest deployment burdens. The device needs to be configured to use correct radio channel and PAN identifier etc. in order for it to communicate with the M2M GW. At the same time, there can be other M2M GWs in the vicinity of the user's GW. This might cause the devices to attach to a wrong M2M GW (e.g. neighbour's M2M GW).
The specification of the Institute of Electrical and Electronics Engineers (IEEE) number 802.15.4-2011 describes how machine-to-machine (M2M) devices can discover wireless personal area network (wireless PAN or WPAN) coordinators by active or passive scanning mechanisms. In active scanning the M2M device sends beacon request frames to a broadcast address on all of its channels and listens to incoming beacon frames. When passive scanning is used, the M2M device goes through all of its channels and listens to periodic beacon frames sent by the WPAN coordinators. The M2M device will store a PANDescriptor from each beacon frame it receives. These descriptions (i.e. PANDescriptor:s) hold configuration information (e.g. WPAN channel, PAN identifier, coordinator address, etc.) about the WPAN network served by the coordinator. After the M2M device has discovered all WPAN coordinators on all channels, it can choose a suitable WPAN and associate itself to the network. The algorithm for choosing the suitable PAN is left outside of the scope of the IEEE specification. Typically, the device chooses to associate itself with the coordinator with the strongest beacon signal, and if the coordinator rebuffs the device, it will try the second strongest and so on. Alternatively or additionally, as described below, the M2M network is set up by an operator who associates each of the devices with a suitable coordinator, one by one.
Wireless short-range networks such as PANs require a lot of manual configuration effort for deployment of devices, update of device configurations (e.g. when devices move between networks from one coordinator to another), when devices are in coverage of overlapping M2M networks. Standard solutions do not provide auto-/zero-configuration for network deployment.
When deploying wireless M2M sensor networks, the network configuration requires manual configuration of all the devices in the network. In order to connect the devices to a wireless M2M network, the network administrator must ensure that each device is using the correct radio channel, addresses, and PAN identifier etc.
If M2M devices are moved between M2M networks, in worst case the configuration must be updated manually in order for the device to connect to the new network. Manual configuration from moving M2M devices is not a scalable model if the M2M devices are required to move unlimitedly.
When multiple M2M networks are configured in the same geographical area (e.g. homes in an apartment building, city centrums, etc.) the M2M devices must be aware of the correct M2M network they belong to. This might become hard when multiple networks are using same configurations between each other.
In addition, automatic security key distribution has not been solved for IEEE 802.15.4. This makes it hard to utilize the built in security features of the standard.